class Point {
    int x,y;
    void setXY(int m,int n) {
        x=m;
        y=n;
    }
}
public class Example4_4 {
    public static void main(String args[]) {
        Point p1,p2;
        p1=new Point();
        p2=new Point();
        System.out.println("p1的引用:"+p1);
        System.out.println("p2的引用:"+p2);
        p1.setXY(1111,2222);
        p2.setXY(-100,-200);
        System.out.println("p1的x,y坐标"+p1.x+","+p1.y);
        System.out.println("p2的x,y坐标"+p2.x+","+p2.y);
        p1=p2;
        System.out.println("将p2地引用赋给p1后:");
        System.out.println("p1的引用:"+p1);
        System.out.println("p2的引用:"+p2);
        System.out.println("p1的x,y坐标"+p1.x+","+p1.y);
        System.out.println("p2的x,y坐标"+p2.x+","+p2.y);
    }
}
